The present invention relates in general to large scale autostereoscopic displays and, more particularly, to a system and method which uses lenslet pixel modules to provide a dynamic, scalable, full-parallax three-dimensional electronic display.
The use of computers to assist in three-dimensional (3D) information design, visualization, and analysis is revolutionizing the communication of 3D information, especially through the emergence of the xe2x80x9cvirtual realityxe2x80x9d paradigm. At present people can interactively experience 3D information using a computer interface which usually requires wearing special glasses or a helmet incorporating goggles. These kinds of solutions are problematic in their unnatural obtrusiveness and difficulty in simultaneous participation of a group or large audience.
Fly""s eye lens sheets and related techniques were developed decades ago using optics and photographic technology. Fly""s eye lens sheets possess many desirable qualities for use in 3D display such as autostereoscopy, high-resolution, full-color, high light efficiency (brightness), full-parallax (both horizontal and vertical depth information), and wide viewing angle (up to about forty-five (45) degrees). Such displays often include a fly""s eye lens sheet having a two-dimensional array of low f-number lenslets which are positioned in front of one or more two-dimensional (2D) images. The 2D image or images are projected into space by the fly""s eye lens sheet. The sum of all rays of light projected from the lenslets approximates the directions and intensities of light rays coming from a real 3D object or scene corresponding with the 2D image or images.
Fly""s eye lens sheets are often considered functionally analogous to lenticular lens sheets which are typically 2D arrays of semi-cylindrical lenslets used in creating 3D images with horizontal parallax only. The resulting lenticular displays have enjoyed more popularity than displays using fly""s eye lens sheets primarily because lenticular lens sheets are technically easier to create. The application of lens sheet techniques to electronic displays is still in an early development stage. Typically, only lenticular lens sheet methods have even been commercially attempted, and only with relatively low resolution displays capable of presenting stereo-image pair views to an observer at a strictly proscribed viewing distance and head positions. Large 3D electronic displays having fly""s eye lens sheets have generally not been considered due to associated costs and difficulty in manufacture and assembly of the display.
There has been previous discussions about developing an optical input/output system having xe2x80x9cprojection pixelsxe2x80x9d with one or more xe2x80x9ccamera pixelsxe2x80x9d interleaved within the array of projection pixels. See for example xe2x80x9cThe I/O Bulb And The Luminous Roomxe2x80x9d prepared by John Stephen Underkoffler published during February 1999 as partial fullfillment the requirements for a doctoral degree from Massachuset Institute of Technology.
In accordance with teachings of the present invention a system and method are provided to produce a scalable, 3D electronic display having a plurality of lenslet pixel modules. For some applications the display will produce a full parallax image. However, a 3D electronic display incorporating teaching of the present invention may be used to produce horizontal parallax only or vertical parallax only images. Each lenslet pixel module is designed in accordance with teaching of the present invention for optimal viewing characteristics such as wide output balanced with practical characteristics such as robustness and ease of manufacture. For one application, a large electronic display may be formed with as many of lenslet pixel modules as necessary to satisfy a given size or element resolution requirement. Fly""s eye lens sheets may be used to form part of each lenslet pixel module. The modular approach of the present invention has many benefits related to image quality, flexibility, and reduced cost.
One aspect of the present invention preferably includes using image display software within an electronic display to provide an independent 3D digital moving image transmission format along with a central control computer for producing and distributing appropriate image information to associated lenslet pixel modules. In addition, a sensor such as a charge coupled device (CCD) can be incorporated into some or all of the lenslet pixel modules so that the resulting 3D electronic display may function as a 3D camera as well as a 3D display. For other applications, the 3D display may include an array of sensor elements interspersed with an array of lenslet pixel modules as opposed to combining sensor elements within respective lenslet pixel modules. For still other applications, there may be a combination of sensor/projector elements, sensor-only elements and projector-only elements as desired for each specific electronic display.
Technical benefits of the present invention include providing autostereoscopic displays which are tailored to the human visual system in characteristics such as resolution and ergonomic ease of use. Technical benefits of such autostereoscopic displays also include presenting 3D information to an individual or group of observers using computer mediated 3D communications in accordance with teachings of the present invention without requiring each observer to wear special goggles or glasses.
Forming an electronic display using one or more fly""s eye lens sheets in accordance with teachings of the present invention provides vertical parallax information which may be very important when it is desirable to view an image from a variety of distances without distortions and when it is desirable to change an observer""s vertical position relative to the display in order to view the associated image from different vertical positions. Fly""s eye lens sheet designs are generally more scalable in resolution and size due to the inherently symmetrical and compact lenslets. Fly""s eye lens sheets generally produce a more realistic, less distorting and easier to view 3D image as compared to a lenticular type display.
The present invention allows using high resolution 2D image sources such as miniature cathode ray tubes (CRTS), liquid crystal displays (LCDs), digital micro device (DMD) mirrors, microelectronicmechanical systems (MEMS) and charge coupled device (CCD) sensors to provide a 2D image at each lenslet pixel module of a 3D electronic display at a reasonable cost. A wide variety of light valves and/or light modulators may be satisfactorily used to provide the desired 2D image preferably in a digital format to each lenslet pixel module. Some of these images sources may be low resolution.
Computer control systems and software may be used to provide an image production and distribution system which presents the desired 2D image behind each lenslet pixel module at a desired frame rate. Miniature CRTS, LCDs, CCD sensors, and other high resolution light valves and light modulators have all recently reached an adequate level of miniaturization and developed into commodities with costs decreasing at a constant rate such that a fly""s eye lens sheet and multiple high resolution 2D image sources may be combined to form a dynamic 3D image display.
Other technical benefits and advantages will be apparent to one of ordinary skill in the art after reviewing the specification, drawings and claims.